- 1[transitive, intransitive] to speak or say something in a quiet voice that is difficult to hear, especially because you are annoyed about something + speech “How dare she,” he muttered under his breath. mutter (something) (to somebody/yourself) (about something) She just sat there muttering to herself. I muttered something about needing to get back to work. mutter that… He muttered that he was sorry.
- 2[intransitive, transitive] mutter (about something) mutter that… to complain about something, without saying publicly what you think synonym grumble Workers continued to mutter about the management.
NAmE//ˈmʌt̮ər//Verb Forms present simple I / you / we / they mutter
he / she / it mutters
past simple muttered
-ing form muttering